Originally, this was the
electronic egg-shaped toy from Japan. (Sooooooo 1997!) It was the first in the trend of virtual pets.
Now the word can be used in a different manner. It can be used to describe a person. When calling someone a "Tomagotchi," you're basically saying that they're needy. Usually needy in an annoying fashion. This, of course, pays homage to
the original toy's constant beeping due to wanting
virtual food or other things...